make structure

add tests
2026-04-22 11:36:38 +00:00 · 2025-10-26 09:15:06 +02:00
parent e71b806e04
commit a7a645c7ab
24 changed files with 326 additions and 133 deletions
@@ -0,0 +1,104 @@
+using System.Collections.Concurrent;
+using System.Net.Http.Json;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using Newtonsoft.Json;
+using SatelliteProvider.Common.Configs;
+using SatelliteProvider.Common.DTO;
+using SatelliteProvider.Common.Interfaces;
+using SatelliteProvider.Common.Utils;
+using SixLabors.ImageSharp;
+
+namespace SatelliteProvider.Services;
+
+
+public class GoogleMapsDownloader(ILogger<GoogleMapsDownloader> logger, IOptions<MapConfig> mapConfig, IHttpClientFactory httpClientFactory)
+    : ISatelliteDownloader
+{
+    private const string TILE_URL_TEMPLATE = "https://mt{0}.google.com/vt/lyrs=s&x={1}&y={2}&z={3}&token={4}";
+    private const string USER_AGENT = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.0.0 Safari/537.36";
+    private const int NUM_SERVERS = 4;
+    private readonly string _apiKey = mapConfig.Value.ApiKey;
+
+    private readonly string _satDirectory = Path.Combine(Directory.GetCurrentDirectory(), "maps");
+
+
+    private record SessionResponse(string Session);
+
+    private async Task<string?> GetSessionToken()
+    {
+        var url = $"https://tile.googleapis.com/v1/createSession?key={_apiKey}";
+        using var httpClient = httpClientFactory.CreateClient();
+        try
+        {
+            var str = JsonConvert.SerializeObject(new { mapType = "satellite" });
+            var response = await httpClient.PostAsync(url, new StringContent(str));
+            response.EnsureSuccessStatusCode();
+            var sessionResponse = await response.Content.ReadFromJsonAsync<SessionResponse>();
+            return sessionResponse?.Session;
+        }
+        catch (Exception e)
+        {
+            logger.LogError(e, "Failed to get session token");
+            throw;
+        }
+    }
+
+    public async Task GetTiles(GeoPoint centerGeoPoint, double radiusM, int zoomLevel, CancellationToken token = default)
+    {
+        var (latMin, latMax, lonMin, lonMax) = GeoUtils.GetBoundingBox(centerGeoPoint, radiusM);
+
+        var (xMin, yMin) = GeoUtils.WorldToTilePos(new GeoPoint(latMax, lonMin), zoomLevel);
+        var (xMax, yMax) = GeoUtils.WorldToTilePos(new GeoPoint(latMin, lonMax), zoomLevel);
+
+        var tilesToDownload = new ConcurrentQueue<SatTile>();
+        var server = 0;
+        var sessionToken = await GetSessionToken();
+
+        for (var y = yMin; y <= yMax + 1; y++)
+            for (var x = xMin; x <= xMax + 1; x++)
+            {
+                token.ThrowIfCancellationRequested();
+                var url = string.Format(TILE_URL_TEMPLATE, server, x, y, zoomLevel, sessionToken);
+
+                tilesToDownload.Enqueue(new SatTile(x, y, zoomLevel, url));
+                server = (server + 1) % NUM_SERVERS;
+            }
+
+        var downloadTasks = new List<Task>();
+
+        for (int i = 0; i < NUM_SERVERS; i++)
+        {
+            downloadTasks.Add(Task.Run(() => DownloadTilesWorker(tilesToDownload, token), token));
+        }
+
+        await Task.WhenAll(downloadTasks);
+    }
+
+    private async Task DownloadTilesWorker(ConcurrentQueue<SatTile> tilesToDownload, CancellationToken token)
+    {
+        using var httpClient = httpClientFactory.CreateClient();
+
+        while (tilesToDownload.TryDequeue(out var tileInfo))
+        {
+            if (token.IsCancellationRequested) break;
+            try
+            {
+                httpClient.DefaultRequestHeaders.UserAgent.ParseAdd(USER_AGENT);
+                var response = await httpClient.GetAsync(tileInfo.Url, token);
+                response.EnsureSuccessStatusCode();
+                var tileData = await response.Content.ReadAsByteArrayAsync(token);
+                using var tileImage = Image.Load(tileData);
+                await tileImage.SaveAsync(Path.Combine(_satDirectory, tileInfo.FileName), token);
+            }
+            catch (HttpRequestException requestException)
+            {
+                logger.LogError(requestException, "Failed to download tile. Url: {Url}", tileInfo.Url);
+            }
+            catch (Exception e)
+            {
+                logger.LogError(e, "Failed to download tile");
+            }
+        }
+    }
+}